Adaptive response to 2 low doses of X-rays in human blood lymphocytes.
Human peripheral blood lymphocytes exposed to a single adaptive dose of 1 cGy X-rays or 2 adaptive doses, each of 1 cGy, were found to be equally resistant to the induction of chromosome damage by subsequent challenge with a high dose of 1 Gy X-rays, as compared to cells that were not pre-exposed. They responded with a significantly reduced incidence of chromatid and isochromatid breaks. These results indicate the presence of an inducible chromosomal repair mechanism in human blood lymphocytes and confirm the observations made by earlier investigators. The incidence of chromosome damage was found to be similar in the lymphocytes pre-exposed to a single or 2 adaptive doses, suggesting that, under the conditions tested, the second adaptive dose did not offer any additional protection against the chromosome damage induced by the challenge dose.
Fan
S
S
Radiation Biology Unit, Paul Scherrer Institute, Villigen PSI, Switzerland.
Vijayalaxmi
Mindek
G
G
Burkart
W
W
D000328:Adult; D002842:Chromatids / Q000528:radiation effects; D002869:Chromosome Aberrations; D004260:DNA Repair / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D006801:Humans; D066298:In Vitro Techniques; D008214:Lymphocytes / Q000528:radiation effects*; D014965:X-Rays